Crepe paper and method



May 15, 1934. R A N 1,958,411

CREPE PAPER AND METHOD Filed Oct. 4. 1930 Patented May 15, 1934 OFFICE v CREPE PAPER AND METHOD 4 Gardner R. Alden,

Framingham, Mass., assignor to Dennison Manufacturing Company, Framingham, Mass., a

corporation of Massachusetts Application October 4, 1930, Serial No. 486,366

12 Claims.

This invention relates to crepe paper and to a method of treating the same with chemical reagents such as fireproofing materials. I

In the art of making crepe paper, the original sheet of flat paper which is used is appreciably shortened by the crinkling or creping operation to which it is subjected, and the amount of shortening is a measure of the degree of creping. The ratio which the length of the original paper sheet employed bears to the length of the creped sheet made therefrom is known as the crepe ratio. While creped papers of relatively low crepe ratio are made and cdmmonly employed for many purposes, those of higher crepe ratios are especially desirable inasmuch as they possess more body, have greater resiliency and elasticity, and may be stretched out to a greater range of lengths, thus adapting them for use in more ways than crepe papers which have a low crepe ratio.

The crepe ratio, which is-attained in any given case, is, to a considerable extent controlled by the degree to which the paper is made to adhere to the creping roll. Accordingly, for producing crepe papers of high crepe ratio, it is customary to treat the sheet with a relatively adhesive creping solution before applying it to the creping roll, so that when it comes into contact with the doctor blade it will be more frequently wrinkled and more tightly folded together and compressed thereby before leaving the surface of the creping roll.

It is frequently desirable to treat crepe papers so as to impart special additional properties thereto, such as fireproofing, coating, coloring, and

the like, without preventing or destroying the high crepe ratio and other desirable properties.

The adhesives which are useful in creping solutions, however, are usually of a colloidal, gelatinous or glue-like nature and consistency.

Such materials generally lose their adhesive properties in the presence of reactive liquids such as solutions of acids, alkalis or ionized salts,- which are ordinarily employed for fireproofing or special coating treatment. Hence, if the sheet of paper to be creped, or the creping solution itself, were treated with such reagents, the creping solution would not manifest sufiicient adhesiveness to permit of producing a creped sheet having a high crepe ratio, nor the required degree of fineness (i. e. number of hills per inch).

On the other hand, if the paper is first creped and then treated with aqueous fireproofing solutions, the wetting of the sheet permits the tightly folded creping to expand, thus stretching the sheet and lowering the crepe ratio.

An object of the present invention, therefore, is to provide a method of preparing crepe paper characterized by having and maintaining a high crepe ratio (e. g. 2 to 1 or more) and the required degree of fineness, and by being adequately treated or even substantially saturated with reagents, such as fireproofing salts which normally render the adhesive ineffective and/or reduce the crepe ratio, or destroy the color of the paper, if already dyed. Other objects will appear fromthe following description.

The method of the invention includes wetting a sheet of paper with an adhesive creping solution (which may also contain an appropriate dye or coloring agent) and then applying the Wet surface of the sheet firmly to a smooth creping surface, such as a creping roll, and treating the exposed, free surface of the sheet with the chemically reactive agent or solution, while the sheet is retained firmly against the creping roll, and subsequently contacting the sheet with a doctor blade, to remove the same, whereupon a close, firmly folded and compressed crepe structure, of high crepe ratio, and degree of fineness is obtained.

A typical mode of carrying out the invention will be described with reference to the accompanying figure which shows diagrammatically, in elevation, a suitable apparatus for treating and creping a sheet of paper.

In operation, a roll of paper 1, such as tissue or other sufliciently soft and suitably wettable paper, is mounted upon a rewinder roll, from which the sheet 3 is drawn over guide roll 2 and thence between a steam heated creping roll 5 and a roll 6. The latter is preferably held firmly against the creping roll and may deposit a suitable adhesive or creping solution 7 thereon from the tank 8. The creping solution is thus applied to the under surface of sheet 3 and penetrates completely through the sheet. In some cases, a flooding bar in place of guide roll 4 may depress the sheet 3 before it reaches the nip of the rolls; more uniformly to distribute the adhesive solution over the sheet.

With thicker sheets of paper or more viscous creping solutions; however, the adhesive may be applied to the upper surface of the sheet, with slight impregnation only or substantially no penetration into the sheet.

A satisfactory creping solution may, for example, consist of five parts of hide glue and five hundred parts of water. This may be used alone,

or with the addition of other reagents, compatible therewith, such as dyes, etc.,-e. g. four parts of tartrazine.

I and as the 'moisture' is driven from the inner surface of the paper, the paper adheres more firmly to the roll.

The sheet, securely attached to the creping roll, may now be treated with a solution of chemically active reagent from the tank 11. This is applied to the outer or exposed surface of the sheet by means of felt roll 12 which dips into the solution and a felt applicator roll 13 which contacts with the first roll, receiving the liquid therefrom in a thin, uniform layer and pressing it firmly against the sheet.

For example, an aqueous solution of a fireproofing salt, such as ammonium sulphate; may

be used. The solution is preferably-relatively concentrated,-e. g. fifty parts of ammonium sulphate to one hundred twenty-five parts of water,and would ordinarily destroy the adhesiveness of the creping solution if added thereto. It may, nevertheless, be applied freely in accordance with this invention and is typical of the solutions or liquids which may be thus employed, such as monoor di-ammonium phosphate.

, The amount of solution applied to the sheet may be controlled by the setting of roll 13 tightly or loosely against the roll 12, and the application of the solution to the sheet may be governed by the consistency of, the roll, the characteristics of the paper and the solution and the pressure with which it is held against the creping roll and sheet of paper. Such adjustments of the rolls maybe madeby usual pressure roll equipment which is well known and need not be described.

The reagent solution may penetrate substantially all the way through the sheet or it may be restricted to a partial depth. For example, if the temperatureof the roll is high and/or the, distance between the rolls 6 and. 13 considerable, the penetration of the reagent solution may be more or less restricted by the'high temperature (which may even cause boiling) and bythe precipitation of glue at and near the inner surface. On the other hand the reagent solution maypenetrate substantially to the inner surface even 'if the sheet contains a large amount of moisture.

at the location in the path of the sheet where the solution is applied. For example, it has been found'that if the machine be adjusted so that a sheet of tissue paper leaves roll 6 with moisture and reaches-roll 13 with 46% moisture,

1,,-Irom-the foregoing it will be "10% of the aforesaid fireproofing solution, at approximately 28 /2% concentrated, can be, intro- "duced into the paper, which is adequate to render the paper fireproof. while this involvesa total moisture content .of 116%, tissue paper is capable of imbibing almost 300% of water. Thus it evident that the degree of impregnation may be regulated by temperature or moisture content as well as in other ways.

the-reagent does not destroy the adhesive conof the sheet'on the creping roll; As the; strikes the doctor blade 16, therefore, it 15 undersood that tightly folded and crinkled before it leaves the creping surface and hence produces a finely creped sheet of high crepe ratio. The creped sheet then passes over guide roll 1'7, drying drum l8, and guide rolls 19, 20, to a take-up roll 21, which constitutes the finished creped, and fireproofed product.

The resulting creped paper produced is characterized not only by a high crepe ratio and an impregnation of reagents normally effective to reduce or to remove the crepe, but also by having a characteristically brilliant surface on the creped side of the sheet while the other surface is that of the natural paper.

The adhesive may be applied to one side of the sheet of paper only, and inso concentrated a form or in such small amount that it will not appre- V of the reactive agents to be appliedto the ex- Q posed or outer surface of the sheet.

Other modifications and applications of the invention will occur to those skilled in the art, in the course of its utilization in actual practice; but such applications are to be considered as included by the above disclosure and within the terms of the following claims.

Lclaim:

1. Method of making crepe paper, comprising as steps leading a sheet of paper to-be creped into adhesive contact with a creping surface, applying a liquid reagent, normally destructive of adhesion, to the exposed surface of the sheet, and creping the sheet from the creping surface.

2. Method of making crepe paper, comprising as steps applying an adhesive to a sheet of paper to be creped, effecting firm adhesive contact of the same with a creping surface, applying a chemically active liquid reagent to the free surface of the sheet, and creping the sheet from the surface.

sive contact of the same with a creping surface,

applying a chemically active liquid reagent to the free surface of the sheet, and creping the sheet from the surface. 1

4. Method of making crepe paper, comprising as steps applying an adhesive to one surface of a sheet of paper to be creped, effecting firm adhesive contact of the same with a creping surface, applying a chemically active liquid reagent to the free surface of the sheet, and creping the sheet from the surface.

5. Method of making crepe paper, comprising as steps applying an adhesive to one surface of a sheet of paper to be creped, effecting firm adhesive contact of the same with a creping surf'ace applying a liquid, normally reactive to renfirm adhesive contact of the same with a creping surface, applying a-liquid, normally reactive with said dyestufi', to the'free surface 'of said sheet, and creping the sheet from the surface.

, '7; Method of making crepe paper, comprising.

as steps applying a colloidal adhesive to a sheet of pap r to be creped, effecting firm adhesive contact of the same with a creping surface, applying a liquid, normally reactive to render said colloidal adhesive ineffective to the free surface of the sheet, and creping the sheet from the surface.

8. Method of making crepe paper, comprising as steps applying a colloidal adhesive and dyestufl to a sheet of paper to be creped, effecting firm adhesive contact of the same with a creping surface, applying a liquid normally reactive with said dyestuff to the free surface of the sheet, and creping the sheet from the surface.

9. Method of making crepe paper, comprising as steps applying an adhesive to a sheet of paper to be creped, efi'ecting firm adhesive contact of the same with a creping surface, applying a liquid, normally reactive to render the adhesive properties of the said adhesive ineffective, to the free surface of said sheet, and creping the sheet from the creping surface.

10. Method of making crepe paper, comprising as steps applying an adhesive and dyestufl to a sheet of paper to be creped, effecting firm adhesive contact of the same with a creping surface, applying a liquid, normally reactive to destroy said dyestuff, to the free surface of said sheet, and creping the sheet from the creping surface.

11. Method of making crepe paper, comprising as steps, applying a creping solution to a sheet of paper to be creped, effecting adhesive contact of the same with a creping surface, expelling a portion of the creping solution from the side of the sheet adjacent said surface, applying a liquid reagent to said exposed side and thereafter creping the sheet.

12. Method of making crepe paper, comprising as steps, applying a creping solution containing dyestuff to a sheet of paper to be creped, efiecting adhesive contact of the same with a creping surface, expelling a portion of the creping solution from the side of the sheet adjacent said surface, applying a liquid reagent to said exposed side and thereafter creping the sheet.

' GARDNER R. ALDEN. 

